CVE-2017-12932 : Vulnerability Insights and Analysis

CVE-2017-12932, published on August 18, 2017, highlights a vulnerability in PHP versions 7.0.x through 7.0.22 and 7.1.x through 7.1.8. The flaw in the ext/standard/var_unserializer.re file can lead to a heap use after free issue when unserializing untrusted data.

Understanding CVE-2017-12932

This CVE entry exposes a critical vulnerability in PHP versions 7.0.x through 7.0.22 and 7.1.x through 7.1.8, affecting the integrity of PHP due to improper handling of untrusted data during unserialization.

What is CVE-2017-12932?

The vulnerability in ext/standard/var_unserializer.re file in PHP versions 7.0.x through 7.0.22 and 7.1.x through 7.1.8 can result in a heap use after free issue when processing untrusted data. The root cause lies in the incorrect usage of the hash API for key deletion in scenarios with an invalid array size.

The Impact of CVE-2017-12932

Exploitation of this vulnerability can potentially compromise the integrity of PHP in an unspecified manner, posing a significant risk to the affected systems.

Technical Details of CVE-2017-12932

This section delves into the technical aspects of the CVE, including the vulnerability description, affected systems, and exploitation mechanism.

Vulnerability Description

The vulnerability in PHP versions 7.0.x through 7.0.22 and 7.1.x through 7.1.8 arises from a heap use after free issue during unserialization of untrusted data, caused by improper hash API usage for key deletion in scenarios with an invalid array size.

Affected Systems and Versions

PHP versions 7.0.x through 7.0.22
PHP versions 7.1.x through 7.1.8

Exploitation Mechanism

The vulnerability can be exploited by manipulating untrusted data during the unserialization process, leading to a heap use after free issue and potentially compromising the PHP integrity.

Mitigation and Prevention

Protecting systems from CVE-2017-12932 requires immediate actions and long-term security practices.

Immediate Steps to Take

Apply patches provided by PHP to address the vulnerability promptly.
Monitor official sources for security advisories and updates related to PHP.

Long-Term Security Practices

Implement secure coding practices to prevent similar vulnerabilities in the future.
Regularly update PHP to the latest secure versions to mitigate potential risks.
Conduct security assessments and audits to identify and address vulnerabilities proactively.

Patching and Updates

Regularly check for patches and updates released by PHP to address CVE-2017-12932 and other security vulnerabilities.